Polar solvents, including dimethylformamide (DMF), have been investigated as anticancer drugs. Their potential usefulness is constrained by hepatotoxic effects. The ability to enhance drug cytotoxicity with ultrasound...
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Electric poling at field intensities approaching the dielectric strength of the film is possible with corona poling. Polymeric thin films with large second-order nonlinearities can be created with this poling techniqu...
Electric poling at field intensities approaching the dielectric strength of the film is possible with corona poling. Polymeric thin films with large second-order nonlinearities can be created with this poling technique. In this paper, the corona poling of nonlinear polymeric films at elevated temperatures, processing, characterization and possible ultrashort-pulse applications are reviewed. An experimental technique is presented to measure the electric field during poling of the nonlinear polymeric film. The characterization of orientational order in corona-poled nonlinear polymeric films and the effects associated with the large electric field during poling are discussed. Poled polymeric thin films are uniquely suited for second-order nonlinear optical applications of ultrashort pulses (< 50 fsec) since minimal pulse spreading occurs. The sum-frequency ultrashort-pulse application of nonlinear polymeric thin films and limitations of the thin polymeric films are discussed. Experimental results are presented of a side-chain nonlinear polymer that is ideally suited for ultrashort-pulse applications.
This paper proposes a new ID-based cryptographic scheme for implementing public-key cryptosystems and signatures. Instead of generating and publishing a public key for each user, the ID-based scheme permits each user ...
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Investigations on the junctions made between Pb and polycrystalline Bi2Sr2CaCu2O8+x (BSCCO) are reported. The BSCCO surfaces were treated with number of methods including mechanically scraping, plasma sputtering, plas...
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Investigations on the junctions made between Pb and polycrystalline Bi2Sr2CaCu2O8+x (BSCCO) are reported. The BSCCO surfaces were treated with number of methods including mechanically scraping, plasma sputtering, plasma oxidation, and Br etch before junctions were fabricated. The current-voltage characteristics and dynamic resistance (dV/dI) vs voltage have been measured at both 77K and 4.2K. We observed, among other features, a Pb gap structure similar to that seen in Pb/YBa2Cu3O7-delta junctions, a magnetic dependent supercurrent, an asymmetric I-V curve, and narrow resistance peaks. Properties of junctions prepared in different manners are compared. Both XPS and electrical studies indicated that Br etch is not suitable for the BiSrCaCuO system in spite of its successful application in YBa2Cu3O7-delta.
We describe a substantive application of the trilinear topographic components /parallel factors model (TC/PARAFAC, due to Möcks/Harshman) to the decomposition of multichannel evoked potentials (MEP's). We pro...
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A simple analysis is presented of reflectance from a stratified uniaxial media with the optic axes parallel or perpendicular to the plane of incidence.
A simple analysis is presented of reflectance from a stratified uniaxial media with the optic axes parallel or perpendicular to the plane of incidence.
A method for applying the topographic components (TC) model to discrimination and classification of multichannel evoked potentials (MEPs) is proposed, and a study designed to demonstrate and test this method is presen...
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A method for applying the topographic components (TC) model to discrimination and classification of multichannel evoked potentials (MEPs) is proposed, and a study designed to demonstrate and test this method is presented. The TC model is used to compare the MEPs of 'normal' and 'abnormal' test subjects to those of a normal reference group, as might be done clinically to screen patients for pathology. The spatial/temporal components identified for the reference group are demonstrated to fit the MEPs of the normal test subjects (not part of the group to which the model was originally fit), but not those of the abnormal test subjects. It is concluded that the TC model can indeed be a useful tool in MEP classification, e.g. in clinical diagnosis, and that further study is warranted along these lines.< >
Blind equalization of systems which contain a nonminimum phase component is a difficult task. Minimizing the energy (l/sub 2/ minimization) of the equalizer output (under a fixed tap constraint) cannot be guaranteed t...
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Blind equalization of systems which contain a nonminimum phase component is a difficult task. Minimizing the energy (l/sub 2/ minimization) of the equalizer output (under a fixed tap constraint) cannot be guaranteed to open the eye (to reliably unscramble the message) because it tends to converge to an equalizer setting that contains a reflection of the unstable zeros inside the unit circle. It is shown that, in at least one simple setup involving a mixture of minimum and nonminimum phase elements, an l/sub infinity / minimization of the equalizer output is the appropriate criterion which should be minimized in order to successfully open the eye. Utilizing a finite impulse response equalizer constrained to have a unity coefficient on the center tap, it is shown that for a large enough dimension (depending on the closeness of the zeros of the channel to the unit circle) the eye will be opened. There is no simple (gradient) scheme to exactly implement the l/sub infinity / minimization. The use of a gradient l/sub p/ scheme for large p is proposed.< >
Quantifying the effect of moisture on the electrical properties of thin dielectric films requires the use of a model that takes into account the geometry of the test structure and the dielectric properties of the air ...
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Quantifying the effect of moisture on the electrical properties of thin dielectric films requires the use of a model that takes into account the geometry of the test structure and the dielectric properties of the air layer above the device. Using this approach, it was found that the electrical properties of dry PI (polyimide) do not change substantially after six weeks of aging at 85 degrees C/85% RH (relative humidity). The dielectric permittivity of PI as a function of %RH increased with aging for excitation frequencies between 12 Hz and 100 kHz. This increase is correlated with observed changes in the surface chemistry of the aged PI film. Shifts in ESCA peak intensities indicate oxidation of the PI surface and deimidization with aging. Possible mechanisms for the observed changes in dielectric properties with aging include a change in the morphology of the bulk PI, resulting in a decreased surface to volume ratio, increased water absorption, a change in the interaction of absorbed water with the PI matrix, and dielectric interfacial effects.< >
作者:
OSTENDORF, DWLEACH, LEHINLEIN, ESXIE, YF1 David W. Ostendorf is an associate professor in the Environmental Engineering Program of the Civil Engineering Department at the University of Massachusetts (Civil Engineering Department
University of Massachusetts Amherst MA 01003). His research interests include unconfined aquifer contamination hazardous waste site remediation and analytical modeling of problems in environmental fluid mechanics. Dr. Ostendorf is a registered professional engineer in Massachusetts and a member of the American Geophysical Union American Society of Civil Engineers Soil Science Society of America Water Pollution Control Federation and Association of Environmental Engineering Professors as well as the National Water Well Association.2 Lowell E. Leach is an environmental engineer with the Robert S. Kerr Environmental Research Laboratory of the U.S. Environmental Protection Agency (RS Kerr Environmental Research Laboratory U.S. EPA P.O. Box 1198 Ada OK74820). Leach received his B.S. ingeological engineering at the University of Oklahoma in 1959 and has been a registered professional engineer in Oklahoma since 1966. With 29 years of experience in field applications of geological engineering he is responsible for developing methodology for sampling ground water and subsurface materials for the Robert S. Kerr Environmental Research Laboratory.3 Erich S. Hinlein is a research assistant in the Environmental Engineering Program of the Civil Engineering Department at the University of Massachusetts (Civil Engineering Department University of Massachusetts Amherst MA 01003). His research interests include ground water pollution hazardous waste site investigation and transport processes in unconfined aquifers. Hinlein graduated with a B.S. in electrical and computer engineering from the University of Massachusetts at Amherst in May 1985 and entered the Environmental Engineering Master's Degree Program in January 1989.4 Yuefeng Xie is a postdoctoral research associate in the Environmental Engineering Program of the Civil E
Two complementary field sampling methods for the determination of residual aviation gasoline content in the contaminated capillary fringe of a fine, uniform, sandy soil were investigated. The first method featured fie...
Two complementary field sampling methods for the determination of residual aviation gasoline content in the contaminated capillary fringe of a fine, uniform, sandy soil were investigated. The first method featured field extrusion of core barrels into pint-size Mason jars, while the second consisted of laboratory partitioning of intact stainless steel core sleeves. The barrel extrusion procedure involved jar headspace sampling in a nitrogen-filled glove box, which delineated the 0.7m thick residually contaminated interval for subsequent core sleeve withdrawal from adjacent boreholes. Soil samples removed from the Mason jars (in the field) and sleeve segments (in the laboratory) were subjected to methylene chloride extraction and gas chromatographic analysis to compare their aviation gasoline content. The barrel extrusion sampling method yielded a vertical profile with 0.10m resolution over an essentially continuous 5.0m interval from the ground surface to the water table. The sleeve segment alternative yielded a more resolved 0.03m vertical profile over a shorter 0.8m interval through the capillary fringe. The two methods delivered precise estimates of the vertically integrated mass of aviation gasoline at a given horizontal location, and a consistent view of the vertical profile as well. In the latter regard, a 0.2m thick lens of maximum contamination was found in the center of the capillary fringe, where moisture filled all voids smaller than the mean pore size. The maximum peak was resolved by the core sleeve data, but was partially obscured by the barrel extrusion observations, so that replicate barrels or a half-pint Mason jar size should be considered for data supporting vertical transport analyses in the absence of sleeve partitions.
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